This invention relates to abrasive products.
Abrasive compacts are used extensively in cutting, milling, grinding, drilling and other abrasive operations. The abrasive compacts consist of polycrystalline diamond or cubic boron nitride particles bonded into a coherent hard conglomerate. The abrasive particle content of abrasive compacts is high and there is an extensive amount of direct particle-to-particle bonding. Abrasive compacts are made under elevated temperature and pressure conditions at which the abrasive particle, be it diamond or cubic boron nitride, is crystallographically stable.
Abrasive compacts tend to be brittle and in use they are frequently supported by being bonded to a cemented carbide substrate. Such supported abrasive compacts are known in the art as composite abrasive compacts. The composite abrasive compact may be used as such in the working surface of an abrasive tool. Alternatively, particularly in drilling and mining operation, it has been found advantageous to bond the composite abrasive compact to an elongate cemented carbide pin to produce what is known as a stud cutter. The stud cutter is then mounted in the working surface of a drill bit or a mining pick.
Recently there has been introduced to the market a composite diamond abrasive compact known as the "claw" cutter. The "claw" cutter has a diamond compact layer on the cemented carbide substrate and in addition a series of grooves formed in the substrate immediately behind the diamond compact layer and containing diamond compact material. During use wear of the compact layer occurs and once this wear reaches the grooved zone, a grooved structure of alternating thick and thin compact ridges develops enabling a longer and more effective abrasive action to take place.
U.S. Patent Specification No. 4,629,373 describes a diamond abrasive compact having enhanced surface irregularities over at least a portion of at least one of the faces to assist in bonding that surface to other materials such as metal by convention mounting techniques. The diamond abrasive compact is used as such without a carbide or metal backing.
European Patent Publication No. 0177466 describes a cutting element for a drill bit comprising a body of a hard material such as cemented carbide having strips of a diamond substance, for example diamond compact, disposed in grooves formed in a cutting face of the body.